1. Field of the Invention
The present invention relates to a light source unit for a semiconductor-type light source of a vehicle lighting device. The present invention also relates to a vehicle lighting device which employs the semiconductor-type light source as a light source.
2. Description of the Related Art
Such a light source unit has been known (see, for example, Japanese Patent Application Laid-open No. 2004-31076). Hereinafter, a related art light source unit will be described. In the related art light source unit, an LED, a resistor, a diode and a conductor are mechanically and electrically connected together with upper and lower contact portions and then assembled to a socket casing. The socket casing includes a mounting unit. The related art light source unit is attached to a vehicle lighting device removable by the mounting unit of the socket casing.
The thus-structured related art light source unit tends to be large in size. In addition, the related art light source unit includes no device to cause heat generated in the LED, the resistor, the diode and the conductor to radiate outward. There is therefore a problem regarding heat radiation in the LED, the resistor, the diode and the conductor.
Problems to be solved by the present invention relate to the large size and the heat radiation in the LED, the resistor, the diode and the conductor in the related art light source unit.